adding go-hello for ch5 lab

Author: richardallred

go-hello/app.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+    "net/http"
+    "flag"
+    "fmt"
+)
+
+var lang = flag.String("lang", "en", "run app with language support - default is english")
+
+func main() {
+    var port = "8080"
+    http.HandleFunc("/", rootHandler)
+    fmt.Printf("Starting server on port %v...\n", port)
+    http.ListenAndServe(":"+port, nil)
+}
+
+func rootHandler(response http.ResponseWriter, request *http.Request) {
+
+    flag.Parse()
+
+    switch *lang {
+      case "en":
+        fmt.Fprintf(response, "Hello %s!. Welcome!\n", request.URL.Path[1:])
+      case "es":
+        fmt.Fprintf(response, "Hola %s!. Bienvenido!\n", request.URL.Path[1:])
+      default:
+        fmt.Fprintf(response, "Error! unknown lang option -> %s\n", *lang)
+  }
+}